I have a very complicated relationship with my beauty, says Charlize Theron

I'm in the corridor of a Beverly Hills Hotel waiting to interview SA's own Charlize Theron. I'd chatted to her three days earlier, when I was fresh out of hospital and ordered to be on bed rest - but - for Charlize? No problem, I could recover later!

While I wait, Seth Rogen approaches. He's paired with the Benoni beauty for the television portion to promote the movie Long Shot - a romantic comedy that will have you chuckling and will leave you with that perfect heart-warming date-night flick feeling.

It's about a guy who's an unlikely romantic partner to the potential next president of the US - played by our gal, Charlize.

Rogen is surprisingly taller than he appears to be on screen, and hovers on the "svelte" side. He's in khakis and a T-shirt that's "interesting". There's a little space of about two strides behind him, and then a bundle of people.

This is Charlize's pod. She's like a skyscraper in a town of little cottages. She is on five inch "bootie-sandals" that open up the arch of her foot, crossed by laces. The naked gash carries your eye up her never-ending shin, to her knee, and on to the stretch of thigh where it meets a designer mini, which she's paired with a blue shirt.

She's chatty and relaxed - with jet black hair - and so self-evidently beautiful that you have to stare at the apparition. It's no wonder she's also the face of Dior's J'adore perfume.

But if you mention her looks, she answers straight: "I know it's a very clichéd thing to say, I get upset when pretty women demur. It's like 'Please, you are f**king gorgeous, stop.' But I was never raised with that being in the forefront.

"In many ways, my life was set up to be a narrative of beauty, getting into the modelling industry, but I didn't like that narrative. There was something inside me that really wanted to fight against that limiting narrative.

"It's only been in the past 10 years that I've come to peace with that and not felt like I always had to prove I wasn't that; that I was something more. It's a sucky thing, but that was the world I was living in at the time.

"I hope my beautiful kids will not have to go through it. I have a very complicated relationship with my beauty because it was almost everything that stood in the way of the thing I really wanted."

She carries herself like one of the guys. She's not "girly". She is pro-women, but can muck around with the boys who test her. They all speak of her with respect.

The number of South African women who have won Oscars can be counted on one hand - with one finger (Janet Suzman was nominated in 1972 for Best Actress in a Leading Role for Nicholas and Alexandra, but didn't win).

Oscar winners don't happen accidentally. Charlize could have been typecast as a lithe blonde decoration - Hollywood is littered with actresses like that. The world washes up a fresh tide of hopefuls in The City of Stars daily and washes out the ones that the city has used up.

No doubt, some power brokers see someone who looks like Charlize and go into Weinstein mode.

The fact that this woman is sitting on the top of the heap, portraying the potential leader of the US in Long Shot, is a tribute to her strength as much as it is to her talent.

And here in tinsel town the gutters are lined with talented people. You've got to not only have "it", you've also got to have the grit to get beyond the masses who press up against the Marilyn Monroe fantasy that shouts: "choose me, I'm different, I'm special".

Charlize is a successful producer, and when asked about directing she gives a mental shrug. "I definitely feel I wouldn't be intimidated by it. I mean, I would be scared shitless, which is usually a good sign for me and that is usually when I go, 'OK, I'll do it'. So I can see that in my future for sure."

There are few actresses that are in her league when you combine Charlize's ability, power and looks, but she moves through the world as though she isn't in an exclusive group. She's, well, South African in her demeanour - no nonsense, hard-working and friendly. But you also get the feeling that if you crossed the line, she'd let you know, so you don't even tip-toe there.

It's not so much in anything she does as it's in her humour; sharp, wickedly funny, naughty. She'll throw in the odd f-bomb, and you just know that she could rumble with the best.

Wonder Woman director Patty Jenkins, who also directed Charlize when she won her Oscar for Monster in 2003, says she'd put her money on Charlize in any fight. That survivor element is evident in the way she spars. Every interview I have with Charlize has me falling off my chair, laughing. Respect. That's the word that hovers around her, and why you don't cross the line. Nicole Kidman has the same quality but it's a little more tightly reined in.

Charlize is aware that she's living a dream. Long Shot is a comedy, full of scenes that call on her to laugh spontaneously.

When asked about manufacturing a laugh on multiple takes that sounds so genuine in the film she talks technique: "There's a lot of pressure in the laughing-out-loud scenes. If it's not natural then you have to try and make it sound natural. Seth's very funny and did something different each take, but it is hard when you have somebody who can't bring that fresh element to every take and you have to turn around and pretend it is the first time you've ever seen something. That is very, very hard."

She lets the truth of the sentence linger in a pause and then with perfect timing and intonation takes it to the absurd. "My job is very hard, let me just be clear. What I do is really, really hard." Her eyes dance at the hyperbole, while the press corp dissolves in giggles, loving her.

Three days earlier, when I rushed into the print press conference, the mother of two adopted African-American children was standing in Dior pumps, right in the doorway, with press milling, getting her makeup touched up. Most hide around the corner pretending that an artist isn't perfecting them. Not Charlize. She moves her mouth away from the lip brush glossing her lips to say "Hi."

We'd done a podcast a few months before and when the overhead lighting made me look like a ghoul next to a superstar, she had one of her people flick on his phone light and hold it to mitigate my shadows.

When I ease onto the chair before the cameras roll, she introduces me to Seth as "a fellow South African". I convey my time restraints: four minutes, two people. She leans in, alert. Nods, promises assistance: "You've got it." "Action" is yelled, and she's just funny. She and Seth riff off each other for a delightful four minutes. When the interview is done, she says: "Get some rest. I'm worried about you."

• 'Long Shot' opens in cinemas on 24 May. Follow Margaret Gardiner on Instagram or on YouTube.